1. Field of the Invention
The present invention relates to a vehicle head light including a light source having a high heat-generation density such as a light-emitting diode, which degrades in light emission efficiency and life span in a high-temperature condition.
2. Description of Related Art
There is known a vehicle head light having a structure in which a projection lens, a reflector and a light source are disposed in this order from its front end, and a heat radiating member is mounted on the light source to radiate heat generated from the light source. For example, refer to Japanese Patent Application Laid-open No. 2004-311224 (Patent document 1), or No. 2009-212019 (Patent document 2).
In the vehicle head light described in Patent document 1, the heat radiating member is formed with a comb-shaped heat radiating fin extending downward. In the vehicle head light described in Patent document 2, the heat radiating member is formed with a plurality of heat radiating fins extending upward or downward.
However, the conventional vehicle head light as described in Patent document 1 or 2 has a problem in that, since the temperature of the heat radiating fin decreases with increasing distance from the light source, and accordingly, the temperature of the distal end of the fin is low, the heat radiation efficiency of the heat radiating member is not high enough for its size, and accordingly the heat radiating member has to be made large in size.